Gemma 4 31B vs GPT-5
For most API use cases (chat, structured outputs, tool calling) Gemma 4 31B is the pragmatic pick: it matches GPT-5 on nearly every internal benchmark while costing a fraction per token. GPT-5 is the better choice when long-context retrieval or math/competition performance matters (it wins long context and posts higher external math scores), but expect vastly higher per-token bills.
Gemma 4 31B
Benchmark Scores
External Benchmarks
Pricing
Input
$0.130/MTok
Output
$0.380/MTok
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GPT-5
Benchmark Scores
External Benchmarks
Pricing
Input
$1.25/MTok
Output
$10.00/MTok
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Benchmark Analysis
Head-to-head in our 12-test suite: GPT-5 wins only long context (GPT-5 = 5 vs Gemma = 4). All other internal tests are ties. Specifics: structured output (both 5) — both models comply with JSON/schema-style outputs in our tests; strategic analysis (both 5) — both handle nuanced tradeoffs equally; tool calling (both 5) — both select and sequence functions accurately in our evaluation; faithfulness, persona consistency, agentic planning, multilingual, classification, constrained rewriting, creative problem solving, and safety calibration are all ties in our testing. Rankings add context: GPT-5 ranks tied for 1st on long context (rank 1 of 55, tied with 36 others) while Gemma ranks 38 of 55 (rank 38 of 55, 17 models share this score) — this gap matters for retrieval or reasoning over 30k+ tokens. On external benchmarks (Epoch AI): GPT-5 scores 73.6% on SWE-bench Verified, 98.1% on MATH Level 5, and 91.4% on AIME 2025; Gemma 4 31B has no external scores in the payload. In short: for end-to-end task parity (structured outputs, tool calling, multilingual, strategy) our tests show a tie; for long-context retrieval and high-end math, GPT-5 has the clear edge.
Pricing Analysis
Costs are radically different. Gemma 4 31B charges $0.13 input and $0.38 output per 1,000 tokens; GPT-5 charges $1.25 input and $10.00 output per 1,000 tokens. Assuming a balanced workload of 1,000,000 tokens/month split 50/50 between input and output: Gemma 4 31B = (500k/1k)$0.13 + (500k/1k)$0.38 = $65 + $190 = $255/month. GPT-5 = (500k/1k)$1.25 + (500k/1k)$10.00 = $625 + $5,000 = $5,625/month. Scale to 10M tokens (50/50): Gemma $2,550 vs GPT-5 $56,250. At 100M tokens: Gemma $25,500 vs GPT-5 $562,500. Who should care: startups, consumer apps, and volume API customers will find Gemma’s pricing transformational; research teams or teams needing the absolute best long-context or top external-math performance may justify GPT-5’s premium.
Real-World Cost Comparison
Bottom Line
Choose Gemma 4 31B if: you need production-grade structured outputs, tool calling, multilingual support, and faithfulness at the lowest cost per token (input $0.13/mTok, output $0.38/mTok), or you operate at high volume where GPT-5’s price is prohibitive. Also choose Gemma if you require a 262,144-token context window with very low per-token cost. Choose GPT-5 if: you need the best long-context retrieval (GPT-5 scored 5 vs Gemma 4 in our tests and ranks 1 of 55 on long context) or superior external math/competition performance (GPT-5: Math Level 5 = 98.1%, AIME 2025 = 91.4% per Epoch AI), and you can absorb its much higher per-token cost (input $1.25/mTok, output $10.00/mTok).
How We Test
We test every model against our 12-benchmark suite covering tool calling, agentic planning, creative problem solving, safety calibration, and more. Each test is scored 1–5 by an LLM judge. Read our full methodology.